Simon Kukes, the man chosen to take over the helm of Russian oil giant Yukos from jailed Russian tycoon Mikhail Khodorkovsky, is no stranger to the energy business.

The 56-year-old new chief executive's career as an oilman spans 25 years, most recently as head of fellow Russian oil major TNK since 1998.

His credentials there include the recent $7.7bn joint venture signed with Britain's BP.

That could mean that talks with ExxonMobil to take a stake in Yukos, in jeopardy after prosecutors froze 44% of Yukos' shares last week, could be back on the cards.

American abroad

Mr Kukes is Russian-born but emigrated to the US in 1977, heading for Texas - the epicentre of the US oil trade - and taking out citizenship thereafter.

The 1980s saw him at Phillips Petroleum and then at Amoco, now part of BP, where he ran the company's business development in the former Soviet Union in the early 1990s.

By 1996 he was back in Russia for his first spell at Yukos. He returned to the company earlier this year.

Mikhail Khodorkovsky retains his controlling stake in Yukos

His status as an expatriate is seen by some as a means of making it more difficult for the Russian government to put direct pressure on him.

Alongside him on the seven-member executive committee which will now run Yukos are two other American citizens: Bruce Midamore, the chief financial officer, and Stephen Theede, who as executive director of Yukos Moscow is the group's effective number two.

However, all are close associates of Mr Khodorkovsky, meaning the close attention being paid to the group by prosecutors and the Russian government may not abate.

Mr Khodorkovsky still votes his controlling stake despite the freeze.

Even though he has stepped down - to pursue "charitable" activities, he said - the feud with President Vladimir Putin over Mr Khodorkovsky's apparent political ambitions is far from over.

No change of direction

In his first outing before the press in Moscow, Mr Kukes was at pains to stress his plans for a smooth handover.

"We don't plan any changes in company behaviour because the company is behaving normally," he told reporters.

"Everything stays intact and we have a strong team."

The first order of business is rebuilding confidence in the massive oil company, whose shares fell more than 20% after Mikhail Khodorkovsky was arrested at gunpoint on Saturday 25 October.

They have since recovered somewhat, jumping on Monday after Mr Khodorkovsky announced he was stepping down and making another 3% gain on Tuesday following Mr Kukes' appointment.

The next is sealing the merger with another Russian oil company, Sibneft, on which shareholders are meant to be voting later this month.

The frozen shares - owned ultimately by Menatep, the bank-based group controlled by Mr Khodorkovsky and his allies - remain votable, so approval of the deal appears a sure thing.

Mr Midamore, the new chief financial officer, promised minority shareholders that they would get a buyout offer by the end of this year.